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Diffstat (limited to 'module/srfi/srfi-26.scm')
-rw-r--r-- | module/srfi/srfi-26.scm | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/module/srfi/srfi-26.scm b/module/srfi/srfi-26.scm new file mode 100644 index 000000000..4a9f4413a --- /dev/null +++ b/module/srfi/srfi-26.scm @@ -0,0 +1,66 @@ +;;; srfi-26.scm --- specializing parameters without currying. + +;; Copyright (C) 2002, 2006, 2010 Free Software Foundation, Inc. +;; +;; This library is free software; you can redistribute it and/or +;; modify it under the terms of the GNU Lesser General Public +;; License as published by the Free Software Foundation; either +;; version 3 of the License, or (at your option) any later version. +;; +;; This library is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +;; Lesser General Public License for more details. +;; +;; You should have received a copy of the GNU Lesser General Public +;; License along with this library; if not, write to the Free Software +;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + +(define-module (srfi srfi-26) + :export (cut cute)) + +(cond-expand-provide (current-module) '(srfi-26)) + +(define-syntax cut + (lambda (stx) + (syntax-case stx () + ((cut slot0 slot1+ ...) + (let loop ((slots #'(slot0 slot1+ ...)) + (params '()) + (args '())) + (if (null? slots) + #`(lambda #,(reverse params) #,(reverse args)) + (let ((s (car slots)) + (rest (cdr slots))) + (with-syntax (((var) (generate-temporaries '(var)))) + (syntax-case s (<> <...>) + (<> + (loop rest (cons #'var params) (cons #'var args))) + (<...> + (if (pair? rest) + (error "<...> not on the end of cut expression")) + #`(lambda #,(append (reverse params) #'var) + (apply #,@(reverse (cons #'var args))))) + (else + (loop rest params (cons s args)))))))))))) + +(define-syntax cute + (lambda (stx) + (syntax-case stx () + ((cute slots ...) + (let loop ((slots #'(slots ...)) + (bindings '()) + (arguments '())) + (define (process-hole) + (loop (cdr slots) bindings (cons (car slots) arguments))) + (if (null? slots) + #`(let #,bindings + (cut #,@(reverse arguments))) + (syntax-case (car slots) (<> <...>) + (<> (process-hole)) + (<...> (process-hole)) + (expr + (with-syntax (((t) (generate-temporaries '(t)))) + (loop (cdr slots) + (cons #'(t expr) bindings) + (cons #'t arguments))))))))))) |